Re^5: Perl's feature to determine, in current point of loop, that this is the last one?

in reply to Re^4: Perl's feature to determine, in current point of loop, that this is the last one?
in thread Perl's feature to determine, in current point of loop, that this is the last one?

Yeah, that's doable. I can also think of doing it without having everything inside the loop ..

#!/usr/bin/perl

use strict;
use warnings;

#  2022-0125: Handle First and List iems differently that everything
#  in between ..

{
    my @keys = qw/q w e r t y u i o p/;

    print "First is $keys[0] ..\n";

    foreach my $k ( @keys[1..(scalar @keys -2)] ) {

      print "In the middle: $k\n";
    }

    print "Finally, we have $keys[-1].\n";
}
[download]

This produces the output

First is q ..
In the middle: w
In the middle: e
In the middle: r
In the middle: t
In the middle: y
In the middle: u
In the middle: i
In the middle: o
Finally, we have p.
[download]

But I like your solution of using an Iterator -- then it has the job of handling the 'first' and 'last' issues.

Alex / talexb / Toronto

Thanks PJ. We owe you so much. Groklaw -- RIP -- 2003 to 2013.

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Re^6: Perl's feature to determine, in current point of loop, that this is the last one? by afoken (Chancellor) on Jan 26, 2022 at 15:49 UTC
Edge case behaviour might need some changes: `#!/usr/bin/perl use strict; use warnings; # 2022-0125: Handle First and List iems differently that everything # in between .. { # my @keys = qw/q w e r t y u i o p/; my @keys = qw/q/; print "First is $keys[0] ..\n"; foreach my $k ( @keys[1..(scalar @keys -2)] ) { print "In the middle: $k\n"; } print "Finally, we have $keys[-1].\n"; }` [download] `B:\>perl 11140865-single.pl First is q .. Finally, we have q. B:\>` [download] Alexander -- Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)	[reply] [d/l] [select]

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Re^6: Perl's feature to determine, in current point of loop, that this is the last one?
by afoken (Chancellor) on Jan 26, 2022 at 15:49 UTC

Edge case behaviour might need some changes:

#!/usr/bin/perl

use strict;
use warnings;

#  2022-0125: Handle First and List iems differently that everything
#  in between ..

{
    # my @keys = qw/q w e r t y u i o p/;
    my @keys = qw/q/;

    print "First is $keys[0] ..\n";

    foreach my $k ( @keys[1..(scalar @keys -2)] ) {

      print "In the middle: $k\n";
    }

    print "Finally, we have $keys[-1].\n";
}
[download]

B:\>perl 11140865-single.pl
First is q ..
Finally, we have q.

B:\>
[download]

Alexander

--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)

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[select]

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